Hello,since we don’t have the Temple in Jerusalem for now,is payment of tithe still valid,if yes to whom? Do we still have recognisable Levites today? What of first fruits?How do we pay it?Is it still relevant today?

Yes, we have thousands of recognized Levites and Kohanim and we still tithe (there are many details involved), but it's only on fruits and vegetables grown in the Land of Israel, and even in Israel, not this year during the Shemitta (= 7th, Sabbatical year). Outside of Israel, Jews tithe 10% of their earnings and give to the poor and yeshiva academies. The first fruits we do not mark anymore (it's also just in the Land of Israel), and accordingly can't and don't have to give them to the Kohanim.